Use a symbolic constant for the default thread count.

Bug 23073037

Change-Id: I7da215ceff23f9a5c8188d3566a7c478b9489117
Reviewed-on: https://swiftshader-review.googlesource.com/3841
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>
2 files changed